Piston of the removable head type



July 26, 1938 w. R. MANSFIELD PISTON OF THE REMOVABLE HEAD TYPE Filed May 21, 1937 Patented July .26, 1938 PATENT OFFICE 2.125.244 v PISTON on THE REMOVABLE HEAD TYPE William R. Mansfield, Fairview, N. J assignor of one-half to John Pimpiano, Grantwood, N. J.

Application May 21, 1937, Serial No. 143,916

3 Claims.

This invention relates to improvements in pistons of the removable head type for internalcombustion engines and the like.

One of the objects of the present invention is,

in a piston of the removable head type, to provide means whereby a sticking or the freezing together of the head and skirt parts and their connections or fastenings will be avoided so as to permit ready removability of a head from the skirt for the purpose of replacement of the entire head or of the rings, and with this end in view, I utilize a construction in which the connecting or fastening members, such as screws, will be protected and shielded against carbon deposits or the like and corrosive factors which would prevent rotation in their sockets or longitudinal movement thereof.

Another object of my invention is to provide the piston head and skirtwith' aligning means and preferably comprising projection onthe head and sockets in the skirt which will enable immediate alignment of the parts during a replacement operation.

Still another object of my invention is to provide a special tool for manipulation of the head during removal and replacement operations.

Still another object of my invention is to provide a piston construction in which a used or worn head may be readily, quickly and easily removed and. a new head of slightly greater diameter may, in many cases, be substituted to compensate for wear of the cylinder and avoid reboring of the cylinder, and both of these removal and replacement operations may be accomplished 35 without disturbing the piston bearings or other parts.

Another object of my invention is to provide a rigid, :strong and durable piston construction in whichembossment will be so arranged and the contact surfacesof the separable head and skirt and of the fastening members therefor will be so minimized or reduced in extent as to avoid any possibility of a sticking of the parts'together, while maintaining strength and rigidity.

With these and other objects in view, the invention comprises the combination of members and arrangement of-parts so combined as to coact and cooperate with each other in the performance of the functions and the accomplish- .through the upper portion of an engine cylinment of the results herein contemplated, and

der showing my improved piston in side elevation;

Fig. 2 is a vertical section through a piston head removed from the skirt;

Fig. 3 is a plan view of the top of my improved piston;

Fig. 3a is a plan view of thebottom surface of my improved piston head;

Fig. 4 is a view in plan of the top of the skirt portion of my piston;

Fig. 5 is a vertical section on the line 55 of Fig. 1 showing the head and skirt in assembled relationship;

Fig. 6 is a fragmentary-vertical section on the line 6-6 of Fig. 4 showing the head and skirt assembled;

Fig. 7 is a fragmentary-vertical section on the line 1-1 of Fig. 4, and

Figs. 8 and 9 are plan and side elevations, respectively, of the special tool employed in the removal and replacement of my piston head.

Referring now to the drawing which illustrates a preferred embodiment of my invention, l indicates a cylinder of an explosive engine which may be of any conventional type and is provided with conventional removable head I. Within such conventional cylinder, I provide my improved piston comprising a skirt portion 2 and a removable or separable head portion 2', and in accordance with my invention the head portion will be so connected and fastened to the skirt portion as to provide, during operation, a construction which will be substantially as rigid and strong as a one-piece structure, but in which the head will be readily removable from the skirt by connecting means which will avoid any sticking or freezing together of the parts and their fastening members owing to corrosion, the deposits of carbon, head and other conditions encountered during'use, and in the preferred form of my invention, such'connecting or fastening members which, of necessity must comprise either screws or bolts, are protected against contact with carbon deposits and other material which would be likely to cause a freezing or sticking of the bolts or screws within their sockets or such a freezing of the parts of the screws to the exposed surfaces as would prevent the turning of such screws, and with these ends in view, I provide the skirt portion at opposite sides of the pin-bearings 3, 3' with embossment members 4, 4', 5, 5' in each of which I provide a counter-sunk socket 6 having a smaller axial bore 1 tapped to receive a screw 8 while-the counter-sunk portion 8 is adapted to receive the lower end of a sleeve 9, the upper end :4, 4', 4 and 4 are slightly lowered so as to leave l a slight space I2 therebetween, and the Web portions 3, 3 and adjacent sections are slightly raised so as to provide contact with adjacent surfaces 3 and 3 of the head.

'It will be seen from the above that the reinforcing webs 3 and 3 are not weakened by bores for screws, but that the top portion of the skirt is strengthened by the positioning of the embossments 4, 4', 5, 5', and that a construction is produced in which the skirt portion will be strong and rigid and will be formed in a single piece and, in the preferred form of my invention illus-- trated, a head member,- also in a single piece, may be so readily, easily and quickly applied thereto or removed therefrom that any unskilled person may remove a head from the skirt portion and' re-apply anew replaceable head. With this end in view, the sleeves 9 are permanently attached or connected in the counter-sunk sockets l0 within the head and are so positioned as to project outwardly, therefrom and by facile manipulation to be aligned with the counter-sunk sockets in the skirt member, after which the screws may be driven home or removed without difliculty.

In the preferred form of my invention, the

screws 8 are preferably limited in their upward movement in any suitable manner so as to project above the top of the piston, as shown in Fig. 2, while the same,v released from the skirt and v in said preferred form of my invention, I preferably utilize a special wrench l3 having a raised handle portion l3 and notched portions H H at opposite ends with the notches in reversed relaticnship so that upon a dropping of the wrench I3 onto the top of the piston a mere turning will cause the notches to engage the upper portions of the shanks of the screws 8 and will permit these upper portions of the shanks of the screws to be utilized as connecting elements for lifting the piston head out-of the cylinder when it is desired to remove the same. The simplicity of these means will be obvious and it will also be obvious that the tool l3 may be also utilized in applying a new piston head to the skirt.

In removing and replacing a piston head it'will only be necessary to loosen the screws 8, which are protected from carbon deposits or other extraneous matter by the sleeves 9, by raising the same to a given limited movement which will release the screw threads from the tapped bore in.

the skirt portion. After thes'e screws are all released, the handle l3 isapplied to any two of the diametrically or diagonally opposite screws -whereupon an upward pull on the handle will readily remove the head from the cyiinder. Likewise, when replacing a new head, the screws will be in substantially the position shown in Fig. 2, whereupon the head may be lowered into'the cylinder and by slight manipulation, the sleeves will find the counter-sunk sockets in the skirt portion and the screws may be driven home against the friction-locking washers 8 whereupon a tight, but readily releasable, connection may be produced between such parts.

It will be obvious that the drawing herewith merely shows one form of my invention and many changes or modifications may be made within the spirit of my invention.

Having described my invention, I claim:--

1. A piston of the removable head type for internal-combustion engines comprising a cylindrical skirt portion having a plurality of radially extending embossments, each provided with a screw-threaded bore surrounded by a countersunk portion, a. piston-head portion provided with sleeves projecting therefrom and adapted to enter said counter-sunk portions, screws passing through the sleeves in said head member and into the bores in said skirt. member.

2. A piston of the removable head type for internal combustion engines comprising a cylindrical skirt portion having sectional piston-pin bearings, aplurality of radially-extending embossments each provided with a screw-threaded bore surrounded by a counter-sunk portion, a piston-head portion provided. with projecting sleeves adapted to enter said counter-sunk portions in the skirt, and fastening screws passing through said head member and projecting sleeves and into said skirt member; said embossments being composed of two pairs, the members of which are positioned in the skirt on opposite sides of said sectional piston-pin bearings.

3; A piston of the removable head type for'internal combustion engines and the like comprising a cylindrical skirt portion having a plurality of inwardly-extending radial embossments, each provided with a bore having a sectional screwthread and a counter-sunk depression surrounding said bore, a piston-head portion provided with embossments aligned with the embossments of said skirt and having projections adapted to enter said counter-sunk depressions in the skirt embossments and also provided with a bore having a complemental screw-thread and passing through said projection and disposed in axial alignmentwith the bore the skirt portion, and screws for said aligned bores, each having a screw-thread adapted to engage both of the sectional internal screw-threads of said aligned bores.

WILLIAM R. 

